What it means
When a business sells on credit, it records the sale as revenue straight away and shows the amount owed as accounts receivable (money owed by customers for goods or services already delivered). The cash does not arrive until the customer pays.
DSO tells you how long that wait lasts on average. A high DSO ties up cash.
A company with strong profits on paper can still run short of money if customers take 90 days to pay while the company must pay staff and suppliers within 30 days. For that reason, lenders, investors and finance teams track DSO closely.
Changes in DSO provide early warnings. A rising figure can mean customers are struggling to pay, credit checks are too lax, invoices are going out late or disputes are not being resolved.
A falling figure can show better collections, but it can also mean the company is being too strict and losing sales. What counts as a good DSO depends on the industry and the payment terms offered.
If a company's terms are 30 days, a DSO of 35 is reasonable, whereas a DSO of 60 signals a problem. Comparing with peers and tracking the trend over time are more useful than chasing one number.
There is also a variant called best possible DSO, which uses only current, not overdue, receivables to show what the figure would be if everyone paid on time. The gap between the normal figure and the best possible figure shows how much of the delay is caused by late payers.
This split helps managers decide whether the problem lies with their terms or with specific customers. Companies improve DSO by invoicing promptly and accurately, checking customers' creditworthiness before offering terms, sending reminders, offering discounts for early payment and following up on overdue accounts.
Some also use invoice financing or factoring, where a finance company advances cash against unpaid invoices. These tools bring cash in faster, but they come at a cost.
In practice
Real-world examples.
Example
A software company bills clients monthly with 30-day terms. Its DSO has crept up from 32 to 48 days over six months. The finance manager finds that large clients are waiting for purchase order numbers and introduces a rule to confirm them before invoicing.
Example
A wholesaler with $12,000,000 of annual credit sales cuts its DSO from 50 to 40 days by chasing overdue accounts. The 10-day improvement releases about $329,000 of cash. The money pays down a bank overdraft.
Example
A bank assessing a loan application for a manufacturer compares its DSO of 75 days with the industry average of 45 days. The credit analyst asks why customers are paying so slowly. The company explains that it has several large customers with long payment terms, and the bank adjusts the loan structure.
Formula
Calculation
DSO = (Accounts receivable / Total credit sales) x Number of days in the period
Worked example: a company has accounts receivable of $300,000 at the end of the year and annual credit sales of $3,650,000. It uses a 365-day year.
Step 1: Credit sales per day = $3,650,000 / 365 = $10,000
Step 2: DSO = $300,000 / $10,000 = 30 days
On average, the company takes 30 days to collect payment. If its terms are 30 days, customers are paying on time, and a rise to 45 days would mean $150,000 more cash tied up in receivables.Case study
Seen in the real world.
Harborview Components is an illustrative, fictional supplier with annual credit sales of $7,300,000, or $20,000 a day. Its receivables stood at $1,000,000, giving a DSO of 50 days against terms of 30 days.
The finance director studied the aged receivables report and introduced three changes: invoices were sent on the day of delivery, reminders went out 5 days before the due date, and a collector phoned any account more than 10 days late. Within six months, receivables fell to $700,000 and DSO to 35 days.
The improvement released $300,000 of cash, which allowed the company to pay suppliers early and earn a 2% discount worth about $18,000 on a $900,000 purchase. The illustrative lesson is that small process changes can produce a large cash benefit.
Watch out
Common mistakes.
- Using total sales instead of credit sales, when cash sales do not create receivables and distort the figure.
- Assuming a lower DSO is always better, when overly strict terms can lose customers.
- Comparing DSO across industries, when payment norms differ widely.
Questions
People also ask.
What is a good DSO?
A good DSO is close to your stated payment terms and in line with industry peers, such as around 30 to 45 days where terms are 30 days.
How do I lower my DSO?
You can invoice promptly, check customer credit, send reminders, offer early payment discounts and follow up on late accounts.
How does DSO relate to cash flow?
Every day of DSO represents a day of sales that is not yet in the bank, so a lower DSO releases cash.
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